COMMENTS ON VITAMIN A SUPPLEMENTATION

Xerophthalmia has disappeared from industrialized countries
during the 20th century in the absence of any special programme to control the
disease. This is undoubtedly due to the improvement in the socioeconomic status
of the population, accompanied by an increased dietary intake of vitamins,
including vitamin A. Better sanitation, lover incidence of childhood diseases
and gastrointestinal infections have certainly contributed to the disappearance
by reducing the overall requirements for vitamin A and preventing a reduced
intake during infectious episodes. The same trends are clearly occurring in a
number of developing countries: this is the case, for instance, of such
countries as Singapore and South Korea, where xerophthalmia has disappeared over
the last thirty years. It is interesting to note that while xerophthalmia has
disappeared, many of these countries are still fortifying some of their foods
with vitamin A: margarine is typical of this practice. While carotenoids are
added for aesthetic reasons, there is no doubt that the addition of retinol is
motivated by nutritional objectives.

Xerophthalmia is still highly prevalent in a number of
developing countries; most of them are located in Asia and in Africa, a few
pockets remaining in Latin America and the Caribbean. In most of these
countries, the socioeconomic situation will not improve at a sufficiently fast
rate for the disease to disappear spontaneously within an acceptable length of
time. Given the present tools available to correct the situation, action must be
taken immediately. There is no doubt that the distribution of large oral doses
of vitamin A constitutes at the present time the most effective answer to the
problem. A programme of distribution can be organized relatively rapidly, using
the health and social structures existing in the country. This type of programme
has often been called an emergency or short-term programme. This appellation is
somewhat misleading as it gives the impression that the programme will be
terminated relatively quickly, say within a few years. However, even if this is
true in some countries approaching a fair level of development, many others
distribution of Vitamin A, especially targeted or medical distribution may be
needed for many years to come if the population, and particularly children, are
to be fully protected against vitamin A deficiency. A good example of this
situation is the prevention of rickets in Europe which was achieved during this
century by the administration of cod liver oil at weekly intervals or, more
recently, using large doses of pure vitamin D once or twice a year. Although
living habits have changed considerably over the last sixty years and children
are commonly exposed to sunlight and provided, therefore, with sufficient
vitamin D, the administration of a vitamin D supplement before and in the middle
of winter is still widely recommended by the paediatricians and practised by
mothers. It seems, therefore, that once a practice has been recognized as useful
by doctors and parents alike, it may take a long time before it is discontinued,
even if it is little or no more justified.

Several delivery systems for vitamin A supplementation have
evolved. The selection of the most appropriate one is largely based on the
strength of the health infrastructure and financial considerations. The
universal distribution is, in principle, the most attractive and the
most effective one. It is very difficult to cover 100% of the child population,
and those who are left out are usually those at greatest risk. Compliance also
decreases with time. The difficulty of reaching all children is illustrated by
the distribution programme in Indonesia. The Nutrition Directorate of Community
Health in the Indonesian Ministry of Health is the authority responsible for the
vitamin A capsule distribution. The latter is carried out through four types of
community outreach programmes, as follows:

1. The Special Vitamin A Distribution Programme is a
vertical activity where single-purpose volunteers distribute capsules twice a
year to children aged 1-6 years, under the supervision of district health
centres (Puskesmas).

2. The Usaha Perbaikan Gizi Keluarga (UPGK), which stands for
Family Nutrition Improvement Effort, is a programme that includes the weighing
of children, distribution of oral rehydration salts and iron tablets, nutrition
education, and help with home and village gardens. Vitamin A capsules are
distributed twice a year.

3. The Nutrition Intervention Project (NIP), which has
broadly-based nutrition activities, includes the distribution of first aid
packages to selected primary health workers in several districts in four
provinces. These packages include vitamin A capsules for distribution every six
months.

4. The BKKBN, a family planning programme, includes a
nutrition package, one of the components of which is the
distribution of vitamin A capsules.

These four distribution systems operate in different parts of
the country, and attempts are being made to test them for efficiency and
results. In Lombok(1), for example, a survey conducted in 1977 revealed a high
prevalence of ocular signs of vitamin A deficiency. The area was subsequently
identified as a priority high-risk area and a massive dose vitamin A
distribution programme was initiated. Vitamin A capsules were distributed using
three systems: the Special Programme, UPGK, and NIP. A particular effort was
made in 1982 to coordinate the activities of the various programmes in order to
make them more effective. Capsule distribution was backed up by radio messages
in order to increase public awareness of the significance of night blindness as
an early sign of nutritional blindness and the importance of giving vitamin A
capsules to children. Information concerning capsule distribution in Lombok is
presented in Table 1.

TABLE 1

VITAMIN A CAPSULE DISTRIBUTION IN LOMBOK, INDONESIA,
1977-1982(number of capsules in thousands)

1978

1979

1980

1981

1982

Special Programme

0

0

88.9

270.7

456.0

UPGK

0

27

68.4

--

--

NIP

5.4

16.2

16.2

36

36

BKKBN

0

0

0

0

0

Total number of capsules

5.4

43.2

173.5

306.7

492.0

Average number of children covered (in 000's)

2.7

21.6

86.7

153.3

246.0

Total number of children covered (percentage)

0.8%

6.8%

27.1%

47.9%

76.9%

The results of the Lombok evaluation indicate that the
prevalence of xerophthalmia decreased dramatically during the period 1977-1982.
The prevalence of Bitot's spots decreased from 1.6% in 1977 to 0.24% in 1983 (p
< 0.01) (See Figure 1). The prevalence of corneal xerophthalmia decreased
from 0.21% in 1977 to 0.04% in 1983 (p < 0.01). While the prevalence of
corneal scars remained about the same - 0.21% in 1977 compared with 0.2% in 1983
- it should be noted that the majority of scars detected in 1983 were more than
two years old.

All data indicate that there is a marked decrease in the
prevalence of xerophthalmia in Lombok since 1977. In the absence of a control
group it is not possible to attribute the decline to the vitamin A distribution
programme alone; other factors such as changes in the socioeconomic status of
the population may also have contributed to the improved situation. One thing is
certain, however: in those areas throughout Indonesia where distribution
programmes have been pursued with diligence, the prevalence of xerophthalmia has
decreased, and in those areas where there are no control programmes, prevalence
has remained stable, or even increased.

The difficulty of reaching a significant percentage of children
is veil illustrated in the case of Indonesia, where it was necessary to set up a
special programme of distribution to achieve a significant coverage.

Dose of Vitamin A. So far, a dose of 200,000 IU of
vitamin A has been used routinely. The vitamin A may be diluted in vegetable oil
or presented in the form of capsules. In some instances, secondary effects such
as nausea, vomiting and headaches, have been observed in a small percentage of
children after administration of the vitamin. If the supplement is given for
medical reasons such as measles, diarrhoea, pulmonary infections or protein
energy malnutrition, there is always the possibility that the administration is
repeated several times, causing eventually a state of hypervitaminosis A and the
occurrence of signs of toxicity. It has, therefore, been suggested that a
smaller dose, say 100,000 IU would be more appropriate when the supervision of
the distribution system is weak. This obviously reduces the length of protection
but insures a greater safety of the programme. These two factors must be
carefully weighed; indeed, it is difficult to use simultaneously the two dosages
for logistic reasons and also because of the danger of confusion among little
trained personnel.

Nutrition education. There is no doubt that sensitization
of the public and especially of the parents is essential for the success of a
distribution programme. All types of media, including radio, TV, newspapers and
posters, can and should be used to achieve this objective.

Another form of supplementation can be achieved through
fortification of food with vitamin A. As mentioned above, this has been
practiced for several decades in many industrialized countries. It can also be
implemented in developing countries provided that the right food vehicle(s) is
identified and that other necessary conditions are fulfilled. A well-designed
food fortification programme has the great advantage of reaching almost
automatically every individual; once the programme has been launched, the cost
is very low in terms of expenses per caput per year. Preparing a fortification
programme cannot be done on a crash basis. Identification of the food
vehicle(s), development of the fortification technology, field testing,
enactment of necessary legislation, setting up control laboratories, training
supervisors and inspectors, are all steps that require some time, usually three
to four years at minimum. Financially sound programmes can be continued over
long periods of time without requiring great expenditures of time or effort.
Over the medium term, fortification programmes whenever they are applicable
constitute an effective alternative to the distribution of supplements.

A number of trials have been undertaken to test the feasibility
and effectiveness of fortifying tea, cooking oil, monosodium glutamate and sugar
with vitamin A. As a result of the studies, sugar has been fortified with
vitamin A since 1976 in Costa Rica, Guatemala, Panama and Honduras.
Fortification was still going on in 1985 in Guatemala and Honduras, whereas it
had been discontinued in Costa Rica and Panama because vitamin A dietary intake
had apparently improved sufficiently so as to make it unnecessary. The changes
in the vitamin A status of the Guatemalan population have been assessed after
one and two years of fortification; these were spectacular in terms of increased
vitamin A concentrations in the blood, liver and breastmilk of almost all
individuals and provide an excellent illustration of the effectiveness of a
veil-designed fortification programme in correcting a nutrient deficiency.

Increasing the vitamin A dietary intake of the population
and especially of young children is obviously the long-term solution. It is
possible in certain cases to achieve this objective in the absence of major
advances in socioeconomic development through nutrition education or through
increased availability of vitamin A-rich foods. Development of horticulture, and
of small husbandry schemes including fish culture can be done independently and
can contribute significantly to the vitamin A intake of the population. Most of
these schemes take a certain time to develop and require capital investment.
There is no doubt that they should be undertaken but one must realize that their
results will not become apparent before a certain time. The right combination of
required measures will vary from country to country and, possibly, from region
to region within countries.

In conclusion, periodic supplementation with large doses of
vitamin A is an effective and possibly the only measure that can be taken on a
crash basis to control xerophthalmia whenever it constitutes a public health
problem. Primary health care can play a major role in facilitating the
distribution of the vitamin A supplements. Once a supplementation programme has
been established, medium- and long-term approaches should be developed which
could lead to a permanent improvement of the vitamin A status of the population.